Rotor disks with rotor blades mounted thereon are known in the prior art in a wide variety of embodiments. They are used for example in gas turbines. The rotor blades have in each case a blade root, a blade airfoil and an outer shroud and are fastened on the rotor disk along a predetermined pitch circle diameter in a uniformly distributed manner. To this end, the blade roots are located in locating slots which are formed in the rotor disk.
During operation, the blade airfoils are subjected to dynamic loads, which can lead to harmful vibrations and to fatigue during high load cycles. This especially applies to long, slender blade airfoils, the natural frequencies of which during the turbine operation frequently lie with the range of the excitation frequencies. This problem can consequently be counteracted by shrouds of adjacent rotor blades being interconnected by means of corresponding connecting elements and being clamped against each other in the cold state. In this way, at low rotational speeds a close contact between the shrouds can be ensured and the natural frequency can be correspondingly manipulated. The pretension can be achieved for example by the rotor blades being twisted with regard to their longitudinal axis during their mounting. To this end, the blade roots of the rotor blades are inserted for example by a few millimeters into the blade root locating slots of the rotor disks and then with a hammer or a press are forced all around into the blade root locating slots. On account of the forces which are required for creating the pretension, limits are set to this method, however, with regard to the degree of achievable pretension.